Heart failure and excess mortality after aortic valve replacement in aortic stenosis

INTRODUCTION

In aortic stenosis (AS), the heart transitions from adaptive compensation to an AS cardiomyopathy and eventually leads to decompensation with heart failure. Better understanding of the underpinning pathophysiological mechanisms is required in order to inform strategies to prevent decompensation.

AREAS COVERED

In this review, we therefore aim to appraise the current pathophysiological understanding of adaptive and maladaptive processes in AS, appraise potential avenues of adjunctive therapy before or after AVR and highlight areas of further research in the management of heart failure post AVR.

EXPERT OPINION

Tailored strategies for the timing of intervention accounting for individual patient's response to the afterload insult are underway, and promise to guide better management in the future. Further clinical trials of adjunctive pharmacological and device therapy to either cardioprotect prior to intervention or promote reverse remodeling and recovery after intervention are needed to mitigate the risk of heart failure and excess mortality.

Valvular heart disease: shifting the focus to the myocardium

Adverse cardiac remodelling is the main determinant of patient prognosis in degenerative valvular heart disease (VHD). However, to give an indication for valvular intervention, current guidelines include parameters of cardiac chamber dilatation or function which are subject to variability, do not directly reflect myocardial structural changes, and, more importantly, seem to be not sensitive enough in depicting early signs of myocardial dysfunction before irreversible myocardial damage has occurred. To avoid irreversible myocardial dysfunction, novel biomarkers are advocated to help refining indications for intervention and risk stratification. Advanced echocardiographic modalities, including strain analysis, and magnetic resonance imaging have shown to be promising in providing new tools to depict the important switch from adaptive to maladaptive myocardial changes in response to severe VHD. This review, therefore, summarizes the current available evidence on the role of these new imaging biomarkers in degenerative VHD, aiming at shifting the clinical perspective from a valve-centred to a myocardium-focused approach for patient management and therapeutic decision-making.

Effect of Sex on Mortality and Left Ventricular Remodeling After Transcatheter Aortic Valve Implantation

BACKGROUND

The effect of sex on mortality is controversial; furthermore, sex differences in left ventricular (LV) remodeling after transcatheter aortic valve implantation (TAVI) remain unknown.

METHODS AND RESULTS

This study included 2,588 patients (1,793 [69.3%] female) enrolled in the Optimized CathEter vAlvular iNtervention (OCEAN)-TAVI Japanese multicenter registry between October 2013 and May 2017. We retrospectively analyzed the effect of sex on mortality, and evaluated changes in the LV mass index (LVMI) after TAVI. Female sex was significantly associated with lower all-cause and cardiovascular mortality (log-rank P<0.001 for both). Multivariate analysis showed that female sex was independently associated with lower cumulative long-term mortality (hazard ratio 0.615; 95% confidence interval 0.512-0.738; P<0.001). Regression in the LVMI was observed in both sexes, and there was no significant difference in the percentage LVMI regression from baseline to 1 year after TAVI between women and men. Women had a survival advantage compared with men among patients with LVMI regression at 1 year, but not among patients with no LVMI regression.

CONCLUSIONS

We found that female sex is associated with better survival outcomes after TAVI in a large Japanese registry. Although LVMI regression was observed in women and men after TAVI, post-procedural LV mass regression may be related to the sex differences in mortality.

Supra-annular versus intra-annular prostheses in aortic valve replacement: impact on haemodynamics and clinical outcomes

OBJECTIVES

The superiority of supra-annular aortic prostheses over intra-annular equivalents in long-term haemodynamics and clinical outcomes remains controversial. This study compared outcomes among patients receiving supra-annular or intra-annular prostheses during aortic valve replacement.

METHODS

We enrolled 587 consecutive patients (mean age 55.1 ± 11.3 years; 188 women) undergoing aortic valve replacement with either supra-annular (n = 316) or intra-annular (n = 271) mechanical prostheses between 2000 and 2016 in our institute. Clinical outcomes and haemodynamic profiles in the 2 groups were compared after propensity score adjustment.

RESULTS

Early death (1.1% vs 0.6%; P = 0.863) was equivalent for both groups. Patients receiving supra-annular prostheses showed a lower rate of patient-prosthesis mismatch (1.2% vs 25.8%; P < 0.001). During a median follow-up of 65 months (quartile 1-3, 30-108 months), overall deaths occurred in 84 (14.3%) patients. The latest echocardiographic assessment in the 136 propensity score-matched pairs demonstrated superior haemodynamics with implantation of supra-annular prostheses: peak velocity (2.7 ± 0.6 vs 2.3 ± 0.5 m/s; P < 0.001), mean pressure gradient (16.5 ± 9.0 vs 12.0 ± 6.2 mmHg; P < 0.001) and left ventricular mass index (113.6 ± 30.3 vs 105.3 ± 26.3 g/m2; P = 0.016). After adjusting with inverse-probability-of-treatment weighting, however, the choice of supra-annular over intra-annular prosthesis did not significantly affect the risk of overall mortality (P = 0.693) or major adverse events: stroke (P = 0.944), infective endocarditis (P = 0.958) and reoperation (P = 0.944).

CONCLUSIONS

The implantation of supra-annular prostheses resulted in superior haemodynamics and left ventricular mass regression, while conferring no apparent clinical benefits. Follow-up studies are required to further evaluate the impact of superior haemodynamics associated with supra-annular prostheses on long-term clinical outcomes.

Hemodynamic assessment of Perceval sutureless bioprosthesis by dobutamine stress echocardiography

OBJECTIVES

The aim of this study was to evaluate the hemodynamic performance of a sutureless bioprosthesis under high workload at mid-term follow-up.

METHODS

Thirty-two patients who underwent isolated aortic valve replacement with a Perceval sutureless bioprosthesis with a minimum follow-up of 1 year were enrolled in this study. S size prosthesis was deployed in 10 patients (31.3%), M size in 9 (28.1%), L size in 8 (25%) and XL size in 5 (15.6%). Effective orifice area (EOA), EOA index (EOAi), and transvalvular gradients were assessed at rest and during dobutamine stress echocardiography (DSE) a median of 19.5 months after surgery.

RESULTS

Dobutamine stress echocardiography (DSE) significantly increased heart rate, stroke volume, ejection fraction, and transvalvular gradients (peak gradient, 24.0 ± 7.6 vs 38.7 ± 13.6 mm Hg, P < .001; mean gradient, 12.6 ± 4.2 vs 19.8 ± 8.3, P < .001). When compared to baseline, estimated valve areas significantly increased at follow-up (EOA, 1.48 ± 0.46 vs 2.06 ± 0.67, P < .001; EOAi, 0.84 ± 0.26 vs 1.17 ± 0.37, P < .001). Mean percentage increase in EOAi was 40.3% ± 28.0%. S size prostheses had the highest increase in EOA1, but the difference was not significant (S 46.0% ± 27.5% vs M 45.4% ± 34.5% vs L 32.7% ± 26.4% vs XL 32.1% ± 20.5%, P = .66). Severe patient-prosthesis mismatch (EOAi ≤ 0.65 cm² /m² ) was present at rest in 8 patients (25%), but only in one patient (3.1%) during DSE.

CONCLUSIONS

The Perceval sutureless bioprosthesis demonstrated good hemodynamics at rest and under high workload. The significant increase in EOAi during DSE suggests the potential advantages of Perceval sutureless bioprostheses in case of small aortic annulus or when patient-prosthesis mismatch is anticipated.

A European Multicenter Study of 616 Patients Receiving the Freedom Solo Stentless Bioprosthesis

BACKGROUND

The purpose of this study was to evaluate the safety and performance of the Freedom Solo valve in aortic valve replacement by clinical and hemodynamic outcomes.

METHODS

Six hundred sixteen patients underwent aortic valve replacement in 18 European centers; mean age was 74.5 ± 5.9 years, 54.1% of the patients were male, and concomitant procedures were performed in 43.2% of the patients. The majority (69%) of the implanted sizes were 23 mm and 25 mm.

RESULTS

At 1 year, overall survival was 94.0%, whereas freedom from valve-related death was 98.6%. There were 9 (1.5%) early (≤ 30 days) and 27 (4.4%) late (>30 days) deaths. Early and late valve-related mortality was 0.3% (n = 2) and 1.1% (n = 7), respectively. Freedom from explant was 97.6%; 10 valves were explanted for endocarditis and 4 for paravalvular leak. There were 10 (1.6%) early and 5 (0.8%) late strokes. Atrioventricular block requiring pacemaker implant occurred in 8 (1.3%) and 1 (0.2%) patients in the early and late postoperative period, respectively. Thrombocytopenia was seen in 27 cases (4.4%) in the early postoperative period. Preoperatively, 93.8% of patients were in New York Heart Association functional classes II through IV, whereas at 1 year 96.9% of patients were in New York Heart Association functional classes I and II. At 1-year follow-up, mean and peak pressure gradients were 7.2 and 14.6 mm Hg, respectively. Indexed left ventricular mass decreased by 12% from 138 g/m(2) at discharge to 122 g/m(2) at 1 year.

CONCLUSIONS

At 1-year follow-up after Freedom Solo implantation, we found acceptable clinical results with low mortality and morbidity and good hemodynamic performance, confirming safety and effectiveness in this multicenter experience.

North American trial results at 1 year with the Sorin Freedom SOLO pericardial aortic valve

OBJECTIVES

A North American prospective, 15-centre Food and Drug Administration (FDA) valve trial was designed to assess the safety and effectiveness of the Freedom SOLO stentless pericardial aortic valve in the treatment of surgical aortic valve disease.

METHODS

Beginning in 2010, 251 patients (mean: 74.7 ± 7.5 years), were recruited in the Freedom SOLO aortic valve trial. One hundred eighty-nine patients have been followed for at least 1 year and are the basis for this review. Preoperatively, 54% of patients had NYHA functional class III or IV symptoms, and the majority of patients had a normal ejection fraction (EF) (median EF = 61%). Concomitant procedures were performed in 61.9% of patients, with coronary artery bypass grafting (CABG) (48.7%) being the most common followed by a MAZE procedure (13.7%). Reoperations were performed in 8.5% of patients in the study.

RESULTS

The entire cohort of 251 patients enrolled had 7 deaths prior to 30 days, 2 of which were valve-related (aspiration pneumonia and sudden death) and 5 were not valve-related. There were 11 deaths after 30 days, 1 valve-related (unknown cardiac death) and 10 not valve-related. Five valves were explanted, 3 early (endocarditis, acute insufficiency and possible root dissection) and 2 late (endocarditis). Thirty-day adverse events include arrhythmias requiring permanent pacemaker (4.2%), thromboembolic events (3.7%) and thrombocytopenia (7.4%). One-year follow-up of all 189 patients demonstrated mean gradients for valve sizes 19, 21, 23, 25 and 27 mm of 11.7, 7.8, 6.3, 4.6 and 5.0 mmHg, respectively. Effective orifice areas for the same valve sizes were 1.2, 1.3, 1.6, 1.8 and 1.9 cm(2), respectively. Ninety-six percent of patients (181/189) were in NYHA class I or II at the 1-year follow-up.

CONCLUSIONS

The Freedom SOLO stentless pericardial aortic valve demonstrated excellent haemodynamics and a good safety profile out to the 1 year of follow-up.

Aortic valve function after bicuspidization of the unicuspid aortic valve

BACKGROUND

Unicuspid aortic valve (UAV) anatomy leads to dysfunction of the valve in young individuals. We introduced a reconstructive technique of bicuspidizing the UAV. Initially we copied the typical asymmetry of a normal bicuspid aortic valve (BAV) (I), later we created a symmetric BAV (II). This study compared the hemodynamic function of the two designs of a bicuspidized UAV.

METHODS

Aortic valve function was studied at rest and during exercise in 28 patients after repair of UAV (group I, n = 8; group II, n = 20). There were no differences among the groups I and II with respect to gender, age, body size, or weight. All patients were in New York Heart Association class I. Six healthy adults served as control individuals. All patients were studied with transthoracic echocardiography between 4 and 65 months postoperatively. Systolic gradients were assessed by continuous wave Doppler while patients were at rest and exercising on a bicycle ergometer.

RESULTS

Aortic regurgitation was grade I or less in all patients. Resting gradients were significantly elevated in group I compared with group II and control individuals (group I, peak 33.8 ± 7.8 mm Hg; mean 19.1 ± 5.4 mm Hg; group II, peak 15.8 ± 5.4, mean 8.2 ± 2.8 mm Hg; control individuals, peak 6.0 ± 1.6, mean 3.2 ± 0.8 mm Hg; p < 0.001). At 100 W peak gradients were highest in group I (group I, 62.7 ± 16.7 mm Hg; group II, 28.1 ± 7.6 mm Hg; control individuals, 15.4 ± 4.6 mm Hg; p < 0.001).

CONCLUSIONS

Converting a UAV into a symmetric bicuspid design results in adequate valve competence. A symmetric repair design leads to improved systolic aortic valve function at rest and during exercise.